(Meth)acrylic acid has been widely used industrially as a starting material of an acrylic resin or a hydrophilic resin. A typical method for producing (meth)acrylic acid is a two-step oxidation method of oxidizing propylene or isobutylene, which are materials derived from fossil resources, into acrolein or methacrolein in vapor in the presence of an oxide catalyst using a fixed-bed multi-tubular continuous reactor, and further oxidizing the product in vapor. Such (meth)acrylic acid, however, has been desired to be produced from a renewable resource, not from a fossil resource.
Now, economical production of (meth)acrylic acid on a commercial scale using a renewable resource such as biomass has been tried. Examples of the method for producing (meth)acrylic acid from biomass include a method of obtaining a saccharide from a natural product (e.g. agricultural product) or by decomposing cellulose or the like substance; fermenting the saccharide to obtain a 3-hydroxycarboxylic acid species such as 3-hydroxypropionic acid (hereinafter, also referred to as 3HP) or 3-hydroxyisobutyric acid; and dehydrating the 3-hydroxycarboxylic acid species.
Patent Literature documents 1 to 7 disclose conventional methods for generating (meth)acrylic acid and methods related to these methods. Patent Literature documents 8 to 10 disclose a method for generating (meth)acrylic acid by pyrolyzing a 3HP polymer by a specific method.